When an emergent event or an urgent matter occurs, it is necessary to ensure that a part of population (such as government workers, firefighters, police, and medical staff) has the priority to use network resources. Even in the case of network congestion, it is also necessary to ensure that this part of the population is capable of properly using network resources.
For an emergent event or an urgent matter, a 3GPP network provides a solution such as the Enhanced Multimedia Priority Service (Enhanced Multimedia Priority Service, eMPS) to ensure that the part of users such as government workers, firefighters, or police who have the access priority is capable of properly using network resources in the case of network congestion. In the case of network congestion or the like, it is ensured that a user with an eMPS capability has the priority to use network resources. Certainly, in other network architecture, a solution for ensuring that the part of users with the access priority has the priority to use network resources may also be called another name, which is not limited herein.
An existing service implementation method cannot ensure that a user with an eMPS capability has the priority to use network resources. In an existing service implementation process, after receiving a downlink data packet of a User Equipment (user equipment, UE) sent by a Packet Data Network Gateway (packet data network gateway, P-GW), a Serving Gateway (serving gateway, S-GW) may trigger a mobility management element to page the UE, so as to deliver the downlink data packet to the UE. The mobility management element may be a Mobility Management Entity (mobility management entity, MME), a Serving GPRS Supporting Node (serving GPRS supporting node, SGSN), or the like.
To avoid that each downlink data packet of the UE received by the S-GW triggers the mobility management element to page the UE, which brings pressure on an air interface, the S-GW may generally adopt the technology of periodically triggering the MME to page the UE or not repeatedly triggering the MME to page the UE before the UE initiates a service request. However, in a practical service implementation process, a UE without an eMPS capability may be transformed to have the eMPS capability or a UE with a low-priority eMPS capability may be transformed to have a high-priority eMPS capability. In this case, if the S-GW has triggered, for a previously received downlink data packet of the UE, the MME to perform paging, the S-GW will trigger the MME to page the UE when the next timing interval arrives or will not trigger the MME to page the UE no matter whether a downlink data packet of the UE subsequently received by the S-GW is a downlink data packet of the UE with the lower-priority eMPS capability or a downlink data packet of the UE with the higher-priority eMPS capability. As a result, the existing service implementation method cannot ensure that a user with an eMPS capability has the priority to use network resources.
Similarly, after receiving the first paging trigger message of the UE, the mobility management element may page the UE through an access network element. After the mobility management element delivers a paging message to the access network element and before the mobility management element receives a paging response message of the UE, the mobility management element will not page the UE for the latter received paging trigger message if the mobility management element receives another paging trigger message of the UE. In this case, no matter whether the latter paging trigger message received by the mobility management element requires a preferential paging service, the mobility management element will not page the UE for the paging trigger message. As a result, the existing service implementation method cannot ensure that a user with an eMPS capability has the priority to use network resources.